Functional connectivity in the human language system:: a cortico-cortical evoked potential study
Functional connectivity in the human language system:: a cortico-cortical evoked potential study
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DOI：
10.1093/brain/awh246
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发表时间：
2004-10-01
期刊：
影响因子：
14.5
通讯作者：
Lüders, HO
中科院分区：
文献类型：
--
作者：
Matsumoto, R;Nair, DR;Lüders, HO
为了更好地理解人类高级皮层功能的机制，需要对皮层功能区域之间的神经元连接有详细的了解。目前还没有很好的方法来跟踪体内神经元的连接。我们用一种新的方法研究了人类语言系统在体内的区域间连接，我们称之为“皮质-皮质诱发电位”（CCEPs）。8例癫痫患者（年龄13-42岁）接受了硬膜下电极有创监测癫痫手术。颈动脉内阿莫巴比妥试验显示，6例患者在栅格植入一侧有语言优势，2例患者有双侧语言表征。采用常规的皮质电刺激来识别前、后语言区。将单脉冲电刺激作用于前语言区（8例）、后语言区（4例）或面部运动区（2例），通过平均时间锁定的基底颞叶语言区和外基底颞叶语言区记录的皮质电图（ecog）获得ccep。在研究过程中，受试者没有被要求执行任何任务。在前语言区刺激诱发了颞上回中部和后部、颞中回邻近部分和边缘上回的外侧颞顶叶区（8名患者中有7名）的ccep。每例患者在3-21个电极上记录ccep。ccep发生在后部语言区域的特定电极上或周围，当受到刺激时，该区域会产生语言停顿。通过刺激前语言区（3例患者中的3例），基底颞区获得了相似的早期和晚期ccep。相比之下，刺激相邻的面部运动区并没有在语言区引起ccep，而是在中央后回引起。刺激后语言区在前语言区（4名患者中的3名）和基底颞区（2名患者中的1名）产生ccep。这些ccep的定义不太明确。这些发现表明，外隐语言区和外隐语言区作为网络的组成部分，通过前馈和反馈投射参与语言系统。与经典的Wernicke- geschwind模型不同，本研究揭示了Broca's区和Wernicke's区之间可能通过弓形束和/或皮质-皮质下-皮质通路双向连接。ccep记录的区域比电刺激识别的后语言区更大。这表明存在一个相当广泛的神经网络，围绕着之前认识到的这一区域的核心区域。
A better understanding of the mechanisms involved in human higher cortical functions requires a detailed knowledge of neuronal connectivity between functional cortical regions. Currently no good method for tracking in vivo neuronal connectivity exists. We investigated the inter-areal connections in vivo in the human language system using a new method, which we termed 'cortico-cortical evoked potentials' (CCEPs). Eight patients with epilepsy (age 13-42 years) underwent invasive monitoring with subdural electrodes for epilepsy surgery. Six patients had language dominance on the side of grid implantation and two had bilateral language representation by the intracarotid amobarbital test. Conventional cortical electrical stimulation was performed to identify the anterior and posterior language areas. Single pulse electrical stimuli were delivered to the anterior language (eight patients), posterior language (four patients) or face motor (two patients) area, and CCEPs were obtained by averaging electrocorticograms (ECoGs) recorded from the perisylvian and extrasylvian basal temporal language areas time-locked to the stimulus. The subjects were not asked to perform any tasks during the study. Stimulation at the anterior language area elicited CCEPs in the lateral temporo-parietal area (seven of eight patients) in the middle and posterior part of the superior temporal gyrus, the adjacent part of the middle temporal gyrus and the supramarginal gyrus. CCEPs were recorded in 3-21 electrodes per patient. CCEPs occurred at or around the particular electrodes in the posterior language area which, when stimulated, produced speech arrest. Similar early and late CCEPs were obtained from the basal temporal area by stimulating the anterior language area (three of three patients). In contrast, stimulation of the adjacent face motor area did not elicit CCEPs in language areas but rather in the postcentral gyrus. Stimulation of the posterior language area produced CCEPs in the anterior language (three of four patients) as well as in the basal temporal area (one of two patients). These CCEPs were less well defined. These findings suggest that perisylvian and extrasylvian language areas participate in the language system as components of a network by means of feed-forward and feed-back projections. Different from the classical Wernicke-Geschwind model, the present study revealed a bidirectional connection between Broca's and Wernicke's areas probably through the arcuate fasciculus and/or the cortico-subcortico-cortical pathway. CCEPs were recorded from a larger area than the posterior language area identified by electrical stimulation. This suggests the existence of a rather broad neuronal network surrounding the previously recognized core region of this area.